If you're an EU citizen, simple make an online request for SikiraPay Mastercard® card by which you can buy Partycoins. The advantage of this card is that it offers you a business opportunity by which you can increase your income.
If you aren't an EU citizen, just ask for a VISA prepaid card in your local bank. Many banks have a one-time noname VISA prepaid card which you can buy and use as any regular VISA card.
Read What are the payment methods at Partyaner for more information.